The deal isn't with Miramax, the money isn't seven figures. Gwyneth Paltrow isn't the star and the book is nearly 30 years old.

All the same, Madeleine Masson seems certain of her place in Guinness World Records. At the age of 92, Mrs Masson, a grandmother, has just sold the film rights of her book.

There is nothing grandmotherly about the book. It is a spy story - a scrupulously authenticated tale of espionage, wartime resistance and heroic feminine derring-do entitled Christine: The Search for Christine Granville.

It tells of events 60 years ago during the second world war. Mrs Masson, who lives in Bosham, West Sussex, published it nearly 30 years ago. But it stirred the blood of a small Canadian film company, Queen Fine Arts, enough for it to sign a deal to pay £57,000 for the film rights.

The company chairman, Bernard Poulin, a Montreal businessman, flew to Britain to meet the astonished and delighted Englishwoman. With him came the Polish actress who will play her heroine, Liliana Komorowska, whose films include The Assignment.

Mrs Masson said: "It's wonderful - quite a surprise. I thought if it ever happened it would be after my death."

Yesterday Guinness World Records said: "We have no one that old listed as selling film rights. We would need to verify it, but it could definitely be a record. This is something we are very interested in."

Mrs Masson has already received £7,000. Under a contract checked by her lawyers, she will receive a further £50,000 whether or not the film is completed. Queen Fine Arts is a small company said to be largely financed by Mr Poulin, a prominent Canadian businessman.

Mrs Masson's biggest joy is that the film will throw renewed limelight on her adored heroine. Christine Granville, who was Polish-born, was awarded the George Medal, OBE and Croix de Guerre for her outstanding bravery working as an allied spy in Poland, Hungary and France.

"She had more ribbons than a general," Mrs Masson said. "She exuded a kind of extraordinary magic - something that set her apart from every other person I've ever met. There was some magnetic force emanating from her."

In the annals of European resistance, Granville is known as Churchill's favourite spy because her information about a Nazi tank build-up on the Russian border supposedly enabled the war leader to warn his Soviet counterpart, Stalin, of an impending attack.

She is also reputed to have had a postwar affair with the James Bond author and intelligence officer, Ian Fleming. But Mrs Masson said she knew of no evidence for this.

Granville became a British agent of the Special Operations Executive after leaving Poland when it fell to the Germans.

She went to Budapest where she met a fellow Pole, Andrew Kowarski-Kennedy, who became her lover. The couple organised the escape of British and Polish prisoners of war. Christine risked her life to return to Poland three times, having to ski through mountain passes to re-enter her homeland.

When she was eventually forced to leave Hungary with Kowarski-Kennedy, she hid in the boot of an ambassador's car as the safest way for her to cross the border.

She was the first woman to be dropped by parachute into France from Algiers when she landed in the south-east of the country in 1944. On the many occasions she was dropped into France she helped to distribute food and pass on messages.

This part of the story has echoes of the Sebastian Faulks novel Charlotte Gray, which was recently made into a film starring Cate Blanchett.

After the war Granville was demobilised, given £100 and ended up working as a stewardess on a passenger liner. Here she met Mrs Masson, a passenger who had spent a year working in the French resistance, and told her story.

Shortly afterwards she was murdered in London by a porter who became obsessed with her. Determined to perpetuate her achievements, Mrs Masson, with her own resistance credentials, was able to persuade SOE veterans, notably Kowarski-Kennedy, to talk to her. Her book, published in 1975, is one of 30 she has written, including a biography of Lady Mountbatten.

She said: "It is very important to protect Christine's memory. Christine was the living emblem of courage. The spectacular virtues of those people who gave their lives for freedom on a daily basis must be honoured."